his efforts on the advantages of using quartz crystals as the transmitting source.13
By April 1917, Langevin was able to test a powerful quartz transmitter at his Toulon laboratory, operating at a “supersonic” frequency of 150 kHz (150,000 cycles per second). During this time, he also experimented with the size of the transmitter surface, the width and intensity of the sound beam, and the frequency. It wasn’t until February 1918, however, that Langevin would successfully test his transmitter at sea, receiving an echo from a submerged submarine for the first time.14
The work Langevin and other French researchers had completed throughout 1915 and during 1916 aroused the interest of British scientists who, representing the British Admiralty’s Board of Invention and Research, established a cooperative relationship with the French Ministry of Inventions. There were indications of a bit of envy by the BIR scientists of the excellent oversight of the research by the ministry, and the importance to the war effort placed on the work of the French scientists.15 From its inception, the BIR, with its emphasis on science, was often at odds with the pragmatic, make-it-happen-now approach of the military.
When America entered the war on April 6, 1917, an ally with a strong scientific tradition took a leading role in the antisubmarine effort. Exchanges of scientific missions began immediately, and the potential importance of Langevin’s transmitter was recognized as a critical topic. The Ames mission from America arrived in France in April, followed by a European mission to America, organized by Painlevé and arriving in Washington at the end of May (chapter 12). The French delegates included two physicists, Charles Fabry and Henri Abraham, who had received commissions as Majors in order that the civilian scientists might better interact with the French military. Several conferences were held in June, where Langevin’s work was discussed, although he was not able to participate in the mission. The conferences resulted in a great deal of enthusiasm among the American scientists, followed by the participants taking immediate action. From Admiral Griffin (1922):
[T]he supersonic work which had been begun in France by professor Langevin was presented in full by Majs. Fabry and Abraham. The New York group, under the direction of Dr. M. I. Pupin, of Columbia University, selected at this time supersonic work at its major activity and continued work on this problem at New York, Key West, and New London, under the direction of the [Special Board on Antisubmarine Devices], during the continuation of the war. The San Pedro group, under Mr. Harris J. Ryan, also started work about this time on supersonic and kindred lines of research.16
Scientists and engineers from universities and industry continued their research on “supersonics” throughout the remaining eighteen months of the war, often bringing their ideas and devices to the Naval Experimental Station in New London. The early experimental work on echolocation is discussed in the epilogue, as this technology would prove to be essential to antisubmarine warfare in the future. The French had planned to install Langevin’s latest device on submarine hunting vessels assigned to the Offensive Division of Torpedo-Listeners and on larger vessels beginning in 1919.17 Armistice intervened.
At the beginning of this section, it was noted that supersonic submarine detection systems using “a beam of sound waves of very high frequency” were not ready for use before Armistice. The British and French antisubmarine efforts had continued throughout the first two-and-a-half years of the war without American help. During those years, U-boats continued their unrelenting pursuit of commercial shipping, which, after their declaration of a war zone around the British Isles in February 1915, resulted in the loss of untold numbers of civilians, including Americans who risked the Atlantic crossing.
CHAPTER 6 LUSITANIA
NOTICE!
TRAVELLERS intending to embark on the Atlantic voyage are reminded that a state of war exists between Germany and her allies and Great Britain and her allies; that the zone of war includes the waters adjacent to the British Isles; that, in accordance with formal notice given by the Imperial German Government, vessels flying the flag of Great Britain, or of any of her allies, are liable to destruction in those waters and that travellers [sic] sailing in the war zone on ships of Great Britain or her allies do so at their own risk. IMPERIAL GERMAN EMBASSY Washington, D.C., April 22, 1915.
—New York Times, May 1, 1915.1
This warning was published in many newspapers, along with a list of the Cunard Line Lusitania’s European destinations, prior to her departure at 10 a.m. on Saturday, May 1, 1915. The German embassy warning was unambiguous—passengers would be traveling “at their own risk.”
On April 30, one day prior to Lusitania leaving New York, Captain Lieutenant Walther Schwieger, in command of U-20, left Wilhelmshaven on Germany’s North Sea coast. Bound for the open seas west of Ireland, his orders were to participate in an aggressive, predatory submarine campaign against merchant vessels. A week later, nearly two thousand passengers and crew of the 787 foot long, 44,060 ton passenger ship would sit in the cross hairs of U-20’s periscope. According to the entry in Schwieger’s log, at 3:10 p.m. on May 7, 1915, “Torpedo shot at distance of 700 meters, going 3 meters below the surface. Hits steering centre behind bridge. Unusually great detonation with large cloud of smoke and debris shot above the funnels. In addition to torpedo, a second explosion must have taken place.”2 It would take only eighteen minutes for Lusitania to plunge to the bottom, just eleven miles from her Liverpool destination, bringing nearly 1200 passengers and crew with her. There were only 761 survivors.3
U-boat flotilla at their base at Keil. U-20, the submarine that sank Lusitania, is in the front row, second from the left. (LOC LC-B2-3292-13)
Headline story about the loss of the Cunard liner Lusitania. (New York Times, May 8, 1915)
When Lowell Thomas, embedded reporter during the war, returned to Europe a decade after Armistice, he searched for German U-boat officers willing to share recollections of their service. The sinking of Lusitania would be of particular importance to Thomas’s telling of the U-boat campaign through the eyes of the participants. He was meticulous in his selection of U-boat officers, whom he interviewed in order to accurately portray their point of view. His Raiders of the Deep was published in 1928, a portrayal of life and death in the German submarine service.
Walther Schwieger could no longer tell his story, having died in September, 1917, while in command of U-88, which was lost in the Terschelling Bight mine fields off the Netherlands coast. Schwieger, however, had described the Lusitania sinking to his fellow submarine officers immediately after U-20 returned. One of these officers was U-boat Commander Max Valentiner, and Thomas used the transcripts of their interview to lend Schwieger’s voice to that tragic event:
“I saw the steamer change her course again. She was coming directly at us. She could not have steered a more perfect course if she had deliberately tried to give us a dead shot. A short fast run, and we waited. The steamer was four hundred yards away when I gave an order to fire. The torpedo hit, and there was rather a small detonation and instantly afterward a much heavier one.”4
When he returned to Wilhelmshaven, Schwieger was congratulated by his peers and throughout his chain of command. Yet the controversy about whether Lusitania was carrying war materials began immediately. Having fired a single torpedo, the second “much heavier” explosion was considered evidence of a cargo of munitions, a claim that Lowell Thomas described as “an alleged statement [by the] Collector of the
